It has become known that over 90% of Down's syndrome individuals develop Alzheimer type dementias as they age. This aging Down's syndrome population is being studied audiologically in comparison to healthy normally aging males and in comparison to Alzheimer's patients. Each Down's syndrome patient receives complete audiologic assessments baseline and serial--including electrophysiological measurements of auditory function. Twenty patients have been seen thus far, all of whom have had some auditory deficit. As this study is ongoing, some preliminary audiologic data are tentatively scheduled to be presented at a large meeting of speech and hearing professionals in November, 1984. Audiologic monitoring of this population is critical for professional and home management, as well as to maintain social and vocational development.